Five people were injured yesterday when seven pipe bombs exploded in mailboxes in rural Illinois and Iowa in what the FBI called an act of domestic terrorism.
US Postal Service officials said the bombs - accompanied by anti-government messages - hurt four postal workers and a mailbox owner, but none of the injuries was life-threatening. One person suffered an eye injury and another received thumb and shoulder wounds.
Two other pipe bombs, found in Iowa mailboxes, failed to detonate and were being rendered safe, authorities said.
The Postal Inspection Service, which is coordinating the investigation, said the bombs were made of steel pipes, each with a 9-volt battery attached.
All the bombs appeared to have been planted in the mailboxes and did not arrive through the mail, the officials said.
"It appears the explosive devices were intended to detonate when they were removed from the mailboxes," Postal Service representative Linda Jensen told a news conference in Des Moines.
The FBI, on heightened alert after the Sept. 11 attacks and deadly doses of anthrax sent through the mail last fall, described the mailbox bombings as "domestic terrorism."